RE: Real Button to trigger DFU for an Buttonless application (nRF52832 / SD V15.0.0)

Vidar Berg — Thu, 06 Sep 2018 09:29:40 GMT

Hello John,

There are probably several ways of achieving this, but I would suggest to try something like this:

1. Start a one off app timer instance once the app detects a button press, and when receiving the timer timeout callback, check if the pin is still pressed. Then perform a soft reset if the pin was pressed for x seconds. Alternatively, poll the input state every second to ensure the button was pressed the entire time.

2. In sdk_config.h header for bootloader, make sure NRF_BL_DFU_ENTER_METHOD_BUTTON is enabled and NRF_BL_DFU_ENTER_METHOD_BUTTON_PIN is assigned to the same pin as the one used by the app. Note: bootloader button initialization need to be changed if your button is not active low.

This way you don't have to use GPREGRET to signal the bootloader to enter DFU mode.

Best regards,

Vidar